I've been using 907s for the past year and they fit my feet just perfectly. A couple months ago I picked up some 790s in the same size. The main difference to me is the greater percentage of mesh on the shoe's upper. The 790s will dry out faster than the 907s so in a hike where it will be raining most of the time, these might be the superior choice. They feel like they hug my feet a little gentler, thought tighter, and the heel is lower. The sole is also lower and they walk lower to the ground. The sole is actually pretty thin so in rocky conditions you feel every rock a bit moreso than with the 907s.
I have used the 790s on day hikes only so far (though some quite long distances and over rugged terrain-just never with a fully loaded pack). So far, I'm pleased with them. They are plenty comfortable and light. Just barely rugged enough for a rocky trail, but they are plenty capable. The drawbacks are these: the toebox seems lower than it is on my 907s in the same size. My right toe touches the end of the shoe in the 790s but does not in the 907s. The toebox is also less protected. There's a slight stiff part in the front center of the shoe, but otherwise your toes are fairly vulnerable to stubbing your foot on a rock (so far this has not happened to me, but it seems a possibility). This has been the main reason I have been hesitant to use them on long hikes (what if it rubs?). If I size up 0.5 sizes from the 907s that I fit into, I think they'd be perfect, but I have yet to do that.
My advice is to give them a try. In the store, try them on and then stand on a downhill slant. Mind whether your toes touch the end of the shoe and if they do, maybe size up a little.
